The present invention relates to pharmaceutical compositions useful for the treatment of a wound or joint, with particular applicability to post operative closed muscular skeletal wounds. The pharmaceutical composition provides alleviation of pain, while promoting healing of the wound and early rehabilitation.
Of major concern in the care of wounds, such as incurred in joint surgery, are relief of post-operative pain, avoidance of infection, hastening of healing, early joint motion, and a decrease in the length of necessary hospital services. Traditional post-operative management of orthopaedic wounds or traumatic wounds have varied in approach. However, an important consideration in the management of wounds is to prevent the painful accumulation of blood and debris and to prevent infection following the formation of an open wound.
Pain relief and reduced swelling can be minimized by leaving a surgical wound or traumatic wound open thereby encouraging the free flow of debris and accumulated fluid out of the wound. Irrigation of the open wound with a sterile solution further promotes the removal of debris, blood, extra-cellular fluid, etc. The same debris and blood in an open wound, however, provide an excellent culture medium for bacterial growth and, hence, such techniques invite infection and promote contamination. Wound closure, conversely, prevents the beneficial flow of debris and fluid from the wound with concomitant pain relief but advantageously reduces the occurrence of bacterial infection and otherwise exterior contamination.
Conventional post-operative management of wounds have sought the benefits of both techniques by closing the wounds but maintaining a drainage tube from the wound through the skin. Closed wound drainage systems, however, have not eliminated infections. The tube can be under no external pressure or vacuum thereby permitting the natural flow of bodily fluids. Since the body does not produce a constant flow of fluid, an open drain tube technique still provides a avenue for infection and contamination.
Moreover, complete removal of debris can be difficult with the sole use of a drain tube. To assist in the removal of debris and fluid from a wound, vacuum drainage systems have been developed to create a negative pressure in the wound. However, vacuum drains have a tendency to promote a flow of contaminates from the skin edges around the tube and back in to the wound. Accordingly, a need exists for an improved system of managing debris and fluid removal from a wound while maintaining a sterile environment.
In addition to the removal of contamination and debris from a wound, post operative management of wounds requires the relief of pain and rehabilitation. Conventionally, pain is treated by the administration of narcotics and/or analgesia to the wound. The treatment of pain relief by means of narcotics, however, has drawbacks such as constipation, drowsiness, stasis pneumonitis, itching, vomiting, confusion and ataxia. Problems associated with epidural analgesia include itching, constipation, increased blood loss, severe ataxia and very expensive multiple injections. Thus, a need exists for new and improved methods for managing pain relief and maintaining a sterile environment.
U.S. Pat. No. 5,616,121, issued to McKay on Apr. 1, 1997, discloses a treatment for alleviating pain in joint wounds through the use of irrigation with a medicinal solution. Irrigation lessens the risk of infection and scar tissue that would otherwise occur from accumulated debris and fluid. The disclosed treatment provides an infusion tubing for infusing a prepared solution into the wound, and a suction tubing for suctioning fluids from the wound. The infusion tubing and suction tubing are joined to communicate with a single tube that is inserted in the wound. Through the use of valves and a controlled pump operation, successive timed intervals of infusion and suction, separated by interruption intervals, bathing of the wound is achieved.
There are several important criteria for use of medical devices in post operative care management of wounds. The risk of adverse health or adverse well being of the patient should be insignificant. Any device that is connected internally to the patient to infuse or subtract fluid should be a closed, sterile system to prevent invasion of environmental contaminants. As patients should be ambulatory as early as possible to prevent deep vein thrombosis, the device should be portable, thereby permitting patient mobility. Mobility also enhances the prospects of early rehabilitation and shortened hospital stay. The administration of drugs for pain relief should have minimal side effects and promote healing.
A continuing need, therefore, exists for a system of managing a post-operative wound which relieves the accumulation of fluid, alleviates or minimizes pain and promotes healing and early rehabilitation.
An advantage of the present invention is a fast-acting, short-lived pharmaceutical composition. The pharmaceutical composition is advantageously capable of being repeatedly or continuously administered to a mammal over a period of time to relieve pain without toxic accumulation of the active ingredients in the mammal.
An additional advantage of the present invention is a medicinal solution capable of being repeatedly or continuously administered to a wound of a mammal which alleviates or minimizes pain and promotes healing and early rehabilitation.
These and other advantages are satisfied, at least in part, by the provision of a pharmaceutical composition comprising at least one local anesthetic, at least one anti-inflammatory agent and at least one antibiotic. In accordance with the present invention, the local anesthetic has a peak effect of no later than about 10 minutes, e.g. no later than about 5 minutes after, administration to a mammal, and the anesthetic and anti-inflammatory have a half-life of no greater than about 36 hours, e.g. no greater than about 8-12 hours, after administration to a mammal. The pharmaceutical composition, thus, advantageously provides rapid relief of pain with a substantially low residual accumulation of active components so that the pharmaceutical composition can be repeatedly or continuously administered to a wound. The pharmaceutical composition can further comprise an anticoagulant to alleviate or minimize detrimental clotting.
Embodiments of the present invention include a pharmaceutical composition comprising Lidocaine as the local anesthetic, Hydrocortisone sodium succinate as the anti-inflammatory agent, Chloramphenicol as the antibiotic agent and Heparin as the optional anticoagulant.
Another aspect of the present invention is a medicinal solution comprising about 0.01 to about 5 weight percent of a local anesthetic, about 0.01 to about 5 weight percent of an anti-inflammatory agent, about 0.01 to about 5 weight percent of an antibiotic, and a carrier, e.g. sterile water. The solution can optionally further include a sufficient amount of an anticoagulant to prevent clotting.
In accordance with the present invention, the medicinal solution can be intravenously, subcutaneously, or directly administered to a wound for treatment thereof. The medicinal solution can be repeatedly or continuously administered to maintain a relatively positive physiological pressure in the wound, e.g., up to about 50 mm/Hg, during and throughout the administration period. By maintaining a relatively positive physiological pressure in the wound, the administration of the medicinal solution enables permeation of the medicinal solution from within the wound to the surface of the wound and seepage therethrough. Seepage of the medicinal solution greatly enhances the process of relieving swelling, inflammation and contamination.
In an embodiment of the present invention, the medicinal solution is continuously and directly administered to the wound with periodic extraction or suction of fluid and/or debris from the wound. Thus, a post-operative joint wound can be cared for by maintaining a relatively positive physiological pressure in the wound during and throughout administration of the medicinal fluid to cause leaking of the infused medicinal solution throughout the wound and through the skin with periodic evacuation of fluid containing blood, debris, extracellular fluid, and/or contaminates thereby promoting early rehabilitation and the alleviation or minimization of pain.
Embodiments of the present invention include a solution comprising up to about 1250 mg of Lidocaine, up to about 400 mg of Hydrocortisone sodium succinate, up to about 1 gm of Chloramphenicol in about 1000 cc of normal saline solution and, optionally, about 1000 units of Heparin.
Additional advantages of the present invention will become readily apparent to those skilled in this art from the following detailed description, wherein only the preferred embodiment of the invention is shown and described, simply by way of illustration of the best mode contemplated of carrying out the invention. As will be realized, the invention is capable of other and different embodiments, and its several details are capable of modifications in various obvious respects, all without departing from the invention. Accordingly, the drawings and description are to be regarded as illustrative in nature, and not as restrictive.